Heat Strip Care & Replacement Guide (Without Getting Electrocuted)

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If there’s one part of an electric furnace that deserves respect, it’s the heat strips.

They don’t look complicated.
They don’t move.
And because of that, they’re easy to ignore.

But heat strips carry high voltage, run extremely hot, and do all the real heating work in an electric furnace. Treat them casually, and you can damage the system—or yourself.

Goodman 68,240 BTU 20 kW Electric Furnace with 2,000 CFM Airflow - MBVK20DP1X00, HKTAD201

This guide walks you through:

What heat strips actually do
How they fail
How to inspect and care for them safely
When replacement makes sense
What not to touch unless you’re trained

No panic. No guesswork. Just smart, safe steps.

🧠 What Heat Strips Do in an Electric Furnace

Heat strips are electric resistance heaters. Think of them like oversized toaster elements built into your furnace.

When powered:

Electricity flows through the element
Resistance creates heat
The blower pushes air across the hot surface
Warm air moves into your home

In many systems, heat strips:

Act as primary heat
Serve as backup or “emergency heat” for heat pumps

If heat strips fail, you don’t get heat—or you get very expensive heat.

Electric heating basics:
👉 U.S. Department of Energy – Electric Resistance Heating
https://www.energy.gov/energysaver/electric-resistance-heating

⚠️ Why Heat Strips Are a Safety Issue

Let’s be clear:

Heat strips operate on high voltage (often 240V).

That means:

Shock risk is real
Arc flash is possible
Burn injuries can happen fast

Mike’s rule

If you’re not 100% sure the power is off, assume it’s on.

No exceptions.

🔌 Step 1: Power Shutdown (The Non-Negotiable Step)

Before opening anything:

Do ALL of the following

Turn the furnace off at the breaker
Confirm no power with a non-contact voltage tester
Wait 15–20 minutes for elements to cool
Keep hands, tools, and jewelry clear

If your furnace has more than one breaker, shut off all of them.

Electrical safety reference:
👉 Electrical Safety Foundation International (ESFI)
https://www.esfi.org/home-electrical-safety/

🔥 Step 2: Visual Inspection of Heat Strips

Once power is confirmed off and panels are removed:

What healthy heat strips look like

Even coloration
Straight elements
No flaking or cracking
Clean mounting points

Red flags

Dark burn spots
Warped or sagging elements
White oxidation or corrosion
Broken coil sections
Melted insulation nearby

If you see physical damage, the strip is done.

🧹 Step 3: Cleaning Heat Strips (Light Only)

Heat strips do not need heavy cleaning.

What you can do

Gently vacuum loose dust nearby
Wipe surrounding metal surfaces
Remove debris that could block airflow

What you should NOT do

Do not scrape the element
Do not use water or cleaners
Do not bend or adjust the strip

Dust acts like insulation. Cleaning nearby surfaces helps the strip shed heat properly.

🌬️ Step 4: Why Airflow Protects Heat Strips

Heat strips rely on airflow to stay within safe temperatures.

Restricted airflow causes:

Overheating
Limit switch trips
Premature element burnout

Check these every time

Clean air filter
Open supply vents
Clear return grilles
No collapsed duct sections

Airflow guidance:
👉 ENERGY STAR – Heating & Cooling Airflow

https://www.energystar.gov/ia/new_homes/features/DuctSystems_062906.pdf

🔍 Step 5: Signs a Heat Strip Is Failing

Heat strip problems don’t always mean “no heat.”

Common symptoms

Heat works, but takes much longer
Lukewarm air instead of hot
Breaker trips during heating
Emergency heat doesn’t engage
Sudden jump in electric bills

These usually mean one stage of heat has failed, not all of them.

🔧 Step 6: Testing Heat Strips (Know Your Limits)

What homeowners can safely do

Visual inspection
Smell check (burnt odor = bad sign)
Check breaker behavior
Observe heating performance

What should be left to professionals

Resistance testing
Amp draw measurement
Contactor and relay testing
Element replacement wiring

Testing requires a multimeter and experience. Guessing here gets expensive—or dangerous.

Heating system maintenance overview:
👉 U.S. Department of Energy – Maintaining Heating Systems

https://www.energy.gov/energysaver/home-heating-systems

🔄 Step 7: When Heat Strip Replacement Makes Sense

Heat strips are modular. You usually replace a strip kit—not the whole furnace.

Replacement is recommended when:

Element is physically damaged
Strip fails resistance testing
Repeated breaker trips occur
Burn marks appear on terminals
Furnace can’t meet heating demand

What replacement involves

Full power isolation
Correct strip sizing (kW matters)
Proper torque on electrical connections
Verifying airflow after install

This is usually a professional job, and that’s okay.

⚡ Step 8: Protecting New Heat Strips from Early Failure

New strips fail early for predictable reasons.

Protect them by:

Changing filters regularly
Keeping blower clean
Avoiding undersized ductwork
Preventing dust buildup
Using surge protection

Surge protection overview:
👉 U.S. Department of Energy – Power Surges
https://www.energy.gov/energysaver/articles/save-energy-your-household-smart-power-strip

📅 Heat Strip Care Schedule That Works

Every 1–3 months

✔ Replace or clean air filter

Once per year

✔ Visual inspection of heat strips
✔ Clean surrounding cabinet
✔ Inspect wiring & insulation

Anytime you smell burning or see discoloration

✔ Shut system down and inspect

❌ Common Heat Strip Myths

“Heat strips don’t need maintenance.”
→ They rely on everything around them being clean and balanced.

“If one fails, they all fail.”
→ Most systems have multiple stages.

“More heat strips = better.”
→ Oversizing raises bills and stresses components.

📋 Quick Safety Checklist (Save This)

✔ Power off at all breakers
✔ Confirm zero voltage
✔ Let elements cool fully
✔ Inspect visually only
✔ Never touch bare terminals
✔ Restore panels before power